17岁的意大利少女梅丽莎（Mar iacute;a Valverde 饰）与母亲和祖母的住在一起，她的生活平淡甚至有些枯燥，每天这个天真纯洁的女孩都在渴望一段浪漫的爱情。某天，梅丽莎和好友参加同学所组织的派对，她邂逅了英俊帅气的男孩丹尼尔（Primo Reggiani 饰）。只是爱情之花并未如期盛开，梅丽莎遭遇了一次带有羞辱性质的性经历，她却从此迷上了这个玩世不恭的男孩。在接下来的日子里，梅丽莎可以引起丹尼尔的注意，而丹尼尔则对她进行各种各样的羞辱。在明白丹尼尔的心意之后，梅丽莎通过放纵来进行报复，她甚至将每段性经历都写入日记 本片根据曾轰动欧洲的真实的少女日记《床前100次梳理乱发》改编。
Melissa lives with her mother and her grandmother in Sicily. She has a close relationship with her grandmother, a heavy smoker, who seems to be the only person in the world who understands Melissa. Melissa's father lives in another country. One day Melissa and her friend go to a party at a school friend's home. While there, Melissa meets Daniele, a boy from the school, and has her first sexual experience. The experience is far from being what Melissa always has dreamed it would be, because Daniele forces her and later forgets her. However, Melissa has fallen in love with Daniele. Back at school, when Melissa tries to get Daniele's attention, he barely remembers her. He takes advantage of Melissa's feelings for him, convincing her to have sex with him whenever he wants. When Melissa discovers Daniele's true motivations, she takes revenge by having even wilder sexual experiences with him and other boys. She even begins keeping a diary to document her sexual experiences. Melissa's mother is worried and tries to approach her distant daughter, while her grandmother is sent off to a rest home.
